高内相乳液法制备聚丙烯酰胺多孔水凝胶及应用

Preparation and application of polyacrylamide porous hydrogel by high internal phase emulsion polymerization

以亲水性二氧化硅纳米粒子(N20)和乳化剂Tween80为复合稳定剂,环己烷为油相制备高内相乳液,再以此乳液为模板制备聚丙酰胺(PAM)多孔水凝胶。乳液光学显微镜照片及PAM多孔水凝胶SEM照片表明N20用量及Tween80用量对材料孔径形貌及直径有直接影响;压汞仪数据表明当N20用量为3%、Tween80用量为9%时,多孔水凝胶平均孔径为38.06nm,孔隙率为77.54%,20h饱和吸水率可达402g/g;吸附实验表明PAM多孔水凝胶对Mn(Ⅱ)具有良好的吸附性能,吸附过程符合准二级动力学方程,属于化学吸附,当溶液pH为4时,120min可达吸附饱和,吸附量为474.64mg/g。

Hydrophilic silica nanoparticles(N20)and emulsifier Tween80 were used as composite stabilizers and cyclohexane as oil phase to prepare high internal phase emulsions(HIPEs).Polyacrylamide(PAM)porous hydrogel was prepared by polymerizing acrylamide in the outer phase with this emulsion as template.The optical microscope photographs of HIPEs and the SEM images of PAM porous hydrogel showed that the amount of N20 and Tween80 affectted the pore appearance and diameter of the material.Mercury injection apparatus results showed that the average pore size of porous hydrogel was 38.06nm,the porosity was 77.54%,and the saturated water absorption rate of 20h reached 402g/g when the dosage of N20 was 3%and Tween80 was 9%.Adsorption experiments showed that PAM porous hydrogel has good adsorption properties for Mn(Ⅱ).The adsorption process conforms to the quasi second-order kinetic equation and belongs to chemical adsorption.When the solution pH was 4,the adsorption saturation reached in 120min and the adsorption amount was 474.64mg/g.